Numerical investigation about the unsteady behavior of a free submerged cavitation jet using the SBES approach

Abstract

Submerged cavitation jet has emerged as an efficient method for the removal of ship fouling. Due to the complicated revolution of cavitation cloud, it has attracted great research interest. Ascertaining the internal flow dynamics of cavitating jets is always a challenge. Thus, this paper investigates the unsteady behavior of a free submerged cavitating jet numerically in three dimensions. The turbulent cavitation flow is simulated utilizing the Stress-Blended Eddy Simulation (SBES) turbulent model combined with the Schnerr-Sauer cavitation model. The results are compared with the data from a famous experiment, and they exhibit good agreement in both time-averaged and unsteady characteristics. The cavitation life stages, i.e., the cavitation growth, shedding, contraction, and collapse are explored. In results, cavitation cloud forms around the jet core. Cavitation cloud shedding involves complex factors, including shear layer instability, complex pressure gradients, and re-entrant motion, and it may also be related to the potential core and jet core instability. Additionally, cavitation cloud development is closely related to the jet core and exhibits synchronous behavior. After the cavitation cloud collapse, a local high pressure is observed and then cavity rebound is generated, where the collapse can be either mild or intensive.